1. Field of the Invention
The present invention relates to a digital TV (DTV), more particularly, a channel selection method used for a digital TV in which user's broadcast preference channels are previously recorded to corresponding keys of a remote controller so that the corresponding keys of the remote controller can be used for selecting preference channels after switching to preference channel selection mode, and a digital TV using the method.
2. Description of the Related Art
As TV technology has been developed from color TV to digital TV, TVs have tended to be remarkably advanced in their technology to higher definition, higher resolution and more multi-functions. Along with these advancements in DTV technology, there have been the pursuits of extreme convenience in selecting TV channels.
FIG. 1 is a structural view of a typical digital TV system according to a prior art.
Referring to FIG. 1, the digital TV system includes an antenna 100, a tuner 102, a demodulator 104, a demultiplexer 106, a decoder 108, a video encoder 110, an audio digital-analogue converter 112, a microprocessor 114, a SDRAM 116, a Flash ROM 118 and an EEPROM 120.
In the operation of the conventional DTV system, the antenna 100 receives and outputs a digital broadcast signal to the tuner 102 which then tunes the received signal. Next, the demodulator 104 receives and demodulates the tuned digital broadcast signal. The demodulated signal is divided into an image signal and an audio signal in the demultiplexer 106.
The divided signal is decoded into an original image and an original voice in the decoder 108. The decoded image is changed into a video format selected by the video encoder 110 to be displayed to the user, and the decoded voice is changed into an analogue signal in the audio digital-analogue converter 112 to be provided to the user.
In addition, the microprocessor 114 controls the whole system of the DTV. The SDRAM 116, the Flash ROM 118, and the EEPROM 120 store data and information and provide processing areas in the system.
In the conventional DTV system, there are three methods for changing channels as follows:
First, there is a method for sequentially changing channels using channel up/down keys of an input device. According to this method, the user should input sequentially channel keys times until a screen corresponding to the desired channel key appears in the DTV screens. In this conventional method, there is a disadvantage in that the user should perform key input operations several times to move to her/his desired channel in the multi-channel DTV system.
Second, there is a method for directly moving to a desired channel by inputting a channel number using a number key. According to this method, the user can directly move to a desirous channel. However, more keys than a number of channel ciphers for one channel change have to be inputted and this may cause an inconvenience. Further more, it is cumbersome to confirm whether or not the input key corresponds to the desired channel.
Third, there is a method for changing channels by moving/selecting a cursor in an OSD (On Screen Display) for providing channel change environment. This method has an advantage to directly change channels, but causes an inconvenience in that the user should input the OSD-enter-keys, direction keys and selection keys several times and a part of video currently displayed in DTV is overlapped with the OSD.
In addition to the above conventional techniques for selecting the desired channels, there is more improved art for changing channels in which the user can previously register preference channels in DTV system, and selects one of the previously-registered preference channels through the OSD by using direction keys and selection keys when watching on DTV. In strict sense, this method belongs to the above-mentioned third conventional method in light that there are still problems that keys are inputted several times and a part of video is overlapped by the OSD.